Why shouldn't I use a 40 volume developer with foils?

I went to Sally’s and told the girl what I was looking for, something that will lift pretty much all the pigment out, I want the hair I’m going to use it on to be white. She gave me L’oreal Quick Blue and Salon Care 40 Volume Developer. Now that I’m home, the Quick Blue package says to use a 20 or 30 volume developer with foils or plastic and a 20, 30, or 40 volume for “open air techniques”.

The problem is I definitely need to use foils or plastic, or I’ll make a huge mess. This has been proven many times.

I can’t find anything online or on the package as to WHY I shouldn’t use 40 volume with foils or plastic. The only thing I can think of is it might be too harsh on the hair.

Insight please?